Preparation And Study Of Flexible Or Transparent Bi_3.25La_0.75Ti₃O₁₂Ferroelectric Memories

The development of flexible or transparent ferroelectric memories is an emerging technological goal in a variety of fields,including electronic skin,wearables,and flexible handheld devices.Perovskite oxide ferroelectric films were widely used in electronic industries.However their application in flexible or transparent devices were limited until now.Many organic ferroelectric films are flexible and transparent despite that their electric properties and temperature stability are inferior to those of perovskite oxide ferroelectric films.Bi3.25La0.75Ti3O12 is famous for the fatigue free characteristic owing to its special Bi-based layered perovskite structure,which makes it one of the best candicates for ferroelectric memories.Here,the flexible memory was successfully prepared with SrRuO3(SRO)bottom electrode,Bi3,25La0.75Ti3O12(BLT)ferroelectric film and Pt top electrode;the transparent memories was successfully prepared with ITO bottom electrode,Bi3.25La0.75Ti3O12(BLT)ferroelectric film and ITO top electrode.In this paper,the flexible and transparent BLT memories were prepared and their properties were studied respectively.This paper mainly consists of the following three aspacts:(1)The flexible Mica/SrRuo3/Bi3.25La0.75Ti3o12/Pt memory(Mica/SRO/BLT/Pt)was successfully prepared by pulsed laser deposition(PLD)on ultrathin Mica substrate.The ferroelectric and dielectric properties of the flexible BLT memory measured at three bending states,i.e.flat state,the 2.2 mm radius state,and the 1.4 mm radius state,were consistent with each other.All flexible BLT memories showed a saturated polarization of?20 ?C/cm2 and a large dielectric tenability of?84%.Most importantly,the ferroelectric polarization did not show obvious fatigue after reading/writing 109 cycles at 100 kHz or being bent to 2.2 mm radius for 10,000 times.(2)The transparent Mica/ITO/Bi.25La0.75Ti3O12/ITO memory(Mica/ITO/BLT/ITO) was successfully prepared by PLD.The transmittance of the transparent memory was more than 80%in the range of visible light.The transparent memory showed a saturated polarization of?20 ?C/cm2 and a large dielectric tunability of>80%.(3)Both the flexible memory and the transparent memory were anti-radiation and high-temperature-resistan to some extent,and they could work normally at 20?-150? or under light illumination(206 nm-650 nm).In summary,these flexible or transparent,high-temperature-resistant and anti-radiation memories are ideal candidates for novel high-performance wearable or optical electronics.